What will it take for Web 3.0 to become mainstream?
When the thing (entertainment) in the title will arrive on it.
Actual content creators, who create content, which wanted to be consumed by content consumers. Both actual content creators and actual content consumers are needed.
For example there is a Facebook group called Heroes of Might and Magic III. This group currently has 118 000 people. Nowadays it is amongst the most successful gaming groups. People post and comment under many funny posts. And most of them are not long content.
This is only one example. I can mention many more. And other type of things too. For example video games.
The main thing is that most people use the internet for entertainment.
There are a lot of different directions that it can go. The structure of Web 2.0 will eventually doom it.
All those content creators in the group you mentioned likely have no stake in FB (Meta). Same with all those on X.